An image forming apparatus, such as a copying machine, optically reads an image of a document set on a document table and prints the read image onto a paper sheet by a printer. The printer includes a photosensitive drum, a charging unit, a developing unit, a transfer unit, a peeling unit, a cleaner, a charge-removal unit, a fixing unit and the like.
In the case where the image forming apparatus as stated above is used, according to use environment, it becomes necessary to adjust, for example, a grid bias voltage of the charging unit, a developing bias voltage of the developing unit or the like. This adjustment work is performed by a service man.
The service man performs a specified operation by a control panel of the image forming apparatus to set an adjustment mode, and further confirms a code corresponding to a part as an object of adjustment by using a manual or the like, and inputs the code. By this input, an input screen relating to the part as the object of the adjustment is displayed by the control panel, and the grid bias voltage or the developing bias voltage can be adjusted by data input to the input screen.
However, with the advance of digitization, colorization, and increase in functionality of the image forming apparatus, the number of codes for adjustment is increased from several hundred to several thousand. It is impossible for the service man to memorize all the codes, and the code must be confirmed by referring to a thick manual at each time of adjustment. Thus, there is a problem that the efficiency of the adjustment work is very poor.
Even if the service man memorizes some codes, in a new type of image forming apparatus, the function is changed, or a new function is added. Thus, it becomes necessary to arrange a group of codes, and it becomes impossible to use the codes memorized at great pains.